One of the most influential factors contributing to the deterioration of existing
pavements is moisture within the pavement structure. Moisture in pavements may enter
the pavement structure in ways such as infiltration through the pavement surface at
cracks, joints, and shoulders. Interrupted aquifers, springs, and drainage in cut areas
may also add to pavement moisture. Excessive moisture in pavements can cause one
or more of the following forms of deterioration: